DIMM vs SODIMM

[Shauny-O]

Can anyone explain the difference between:

- 8 GB PC3-12800 DDR3L (2 DIMM)

and

- 8 GB PC3-12800 DDR3L SDRAM 1600MHz SODIMM

Both are being offered as options on a Lenovo E540 I'm considering purchasing.

Thanks

 

[scout_03]

give the link usualy all laptop use sodimm memory module could be a print error .

 

[SchizTech]

DIMM is a memory module (Dual Inline Memory Module)
while SODIMM is the technical term for laptop RAM (Small Outline DIMM)

The difference in terminology is meaningless, if confusing

 

[SchizTech]

When you say both are options, where are you seeing this though? If both are on the Lenovo site it's just an odd difference in terminology

 

[ahmeday2012]

Dimm is for desktop pcs.
Sodimm is for laptops.
The difference is the size.
Hope that helps

 

[Shauny-O]

That's what I couldn't understand. Yes, it's on the Lenovo website:

http://shop.lenovo.com/gb/en/laptops/thinkpad/edge-series/e540/#tab-customize

 

[scout_03]

this look to me as a error when they made the page since the sodimm is the same price and if you press any of them the other got a zero value .

 

[Pinhedd]

Can anyone explain the difference between:

- 8 GB PC3-12800 DDR3L (2 DIMM)

and

- 8 GB PC3-12800 DDR3L SDRAM 1600MHz SODIMM

Both are being offered as options on a Lenovo E540 I'm considering purchasing.

Thanks

DIMMs are used is commercial desktop computers (for those that do not have the memory ICs soldered directly to the motherboard anyway) whereas SODIMMs are used in compact portable computers such as notebooks and netbooks (again, for those that do not have the ICs soldered directly to the motherboard).

The two formfactors are nearly identical in performance but differ in formfactor. DDR3-DIMMs have 240 pins, whereas DDR3-SODIMMs have 204 pins and are approximately half as wide.

Reducing the pin count by 36 requires some technical sacrifices, but the sacrifices that are made apply mostly to server and workstation class computers. For example,

■ DDR3-SODIMM specify only two Chip-Select lines per memory channel whereas DDR3-DIMM specifies four. This allows for up to four ranks per channel using a SODIMM formfactor or 16 ranks per channel using a DIMM formfactor. There are typically two ranks per DIMM (one per side) with only expensive server modules having four or eight. Combined with a typical one or two DIMM/SODIMM slots per channel, 4 is rarely ever exceeded using commercial components.

■ DDR3-SODIMM specifies 14 address lines per memory channel whereas DDR3-DIMM specifies 16. This encourages the use of wider ICs for SODIMMs (16 IO pins per IC for SODIMM rather than 8 for DIMM) to reduce the number of address lines needed.

■ There is no support for parity or ECC under any SODIMM formfactor (this frees up at least 10 pins alone)

■ The Data Queue Strobe is 9 bits on DDR3-DIMM, but only 8 bits on DDR3-SODIMM

Most of these have no impact on consumer hardware, but the use of 16 bit DRAM ICs rather than 8 bit DRAM ICs does mean that SODIMMs tend to cost more than DIMMs of equivalent capacity and speed.

 

[jab_bauer]

- 8 GB PC3-12800 DDR3L (2 DIMM)
2 DIMM means they are using two 4GB sticks to get you to 8GB

- 8 GB PC3-12800 DDR3L SDRAM 1600MHz SODIMM
This means they are using one 8GB stick.

You will have two slots total in your laptop, so if you wish to upgrade your RAM in the future, you will need to replace both sticks in the case of 2 DIMM, or simply add another 8GB stick in the case of SODIMM.